Semiconductor device having a hall-effect element

ABSTRACT

A first and a second Hall element ( 2  and  3 ) for current detection, in addition to a semiconductor element ( 4 ) for an electric circuit, are provided on a semiconductor substrate. A conductor layer ( 5 ), through which flows the current of the semiconductor element ( 4 ), is formed on an insulating film ( 20 ) on the surface of the semiconductor substrate. The conductor layer ( 5 ) is arranged along the first and second Hall elements ( 2  and  3 ) for higher sensitivity. The magnetic flux created by the flow of a current through the conductor layer ( 5 ) is applied to the first and second Hall elements ( 2  and  3 ). The first and second Hall voltages obtained from the first and second Hall elements ( 2  and  3 ) are totaled for higher sensitivity.

This application was filed under 35 U.S.C. § 371 and claims priority ofPCT application Ser. No. JP99/05408, filed Oct. 1, 1999.

TECHNICAL FIELD

The present invention relates to a semiconductor device having aHall-effect element or elements for current detection.

BACKGROUND ART

Integrated semiconductor circuits have been known in which a Hall-effectelement or elements, built on the proportionality of the Hall voltage ofa semiconductor to the applied magnetic field, and an amplifier oramplifiers for the Hall-effect element or elements are formed on aunitary semiconductor substrate.

Conventionally, however, the integrated circuits including Hall-effectelements have been used solely for detection of external magnetic fields(those applied from without the integrated circuits) and not fordetection of input and output currents of other semiconductor elementswithin the integrated semiconductor circuits. Additionally, the priorart integrated circuits have not possess sufficient sensitivity todetect currents of relatively small magnitude flowing inside thecircuits. Also, the integrated circuits including Hall-effect elementshave not been constructed to be free from the influence of undesiredexternal magnetic fields.

It is therefore an object of this invention to provide a semiconductordevice capable of accurately and easily detecting the currents ofelectric circuits by a Hall-effect element.

DISCLOSURE OF INVENTION

The current-detecting semiconductor device according to the presentinvention comprises a semiconductor substrate having a Hall-effectelement, an insulating film disposed on a surface of the semiconductorsubstrate, and a conductor layer disposed on the insulating film so asto extend along the Hall-effect element as seen in a planar view and soformed as to permit an electric current of an electric circuit to flowtherein.

Thus the conductor layer for carrying a current to be detected can bedisposed close to the Hall-effect element. As a result, the current canbe accurately detected by the Hall-effect element. Also, the positionalrelationship between the Hall-effect element and the conductor layer canbe accurately and easily determined, resulting in the reduction offluctuations of the values detected.

Desirably, the conductor layer should be so formed as to surround theHall-effect element in order to augment the amount of magnetic fluxapplied to the Hall-effect element.

It is also desirable to provide a first and a second Hall-effect elementand to arrange the conductor layer so that magnetic fields may beapplied to the first and the second Hall-effect element in oppositedirections, for enhancement of current-detecting sensitivity andsuppression of noise.

It is also desirable to provide a Hall-effect element or elements andanother circuit element on the same semiconductor substrate for theprovision of a compact and inexpensive semiconductor device having aHall-effect element.

It is also desirable to provide a magnetic collector in order to causethe magnetic flux that has been produced by the current carried by theconductor layer, to work effectively on the Hall-effect element.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view schematically illustrating a first preferred formof integrated circuit including a Hall-effect element according to theinvention.

FIG. 2 is a circuit diagram of a d.c.-to-d.c. converter built on theprinciples of the integrated circuit of FIG. 1.

FIG. 3 is a fragmentary plan view showing the integrated circuit of FIG.1 in more detail.

FIG. 4 is a sectional view of the first preferred form of integratedcircuit, taken along the line A—A in FIG. 3.

FIG. 5 is a sectional view of the first preferred form of integratedcircuit, taken along the line B—B in FIG. 3.

FIG. 6 is a plan view of the semiconductor substrate seen in FIG. 4.

FIG. 7 is a fragmentary plan view of a second preferred form ofintegrated circuit according to the invention.

FIG. 8 is a section through the integrated circuit of FIG. 7, takenalong the line C—C therein.

FIG. 9 is a view similar to FIG. 1 but showing a third preferred form ofintegrated circuit according to the invention.

FIG. 10 is a plan view similar to FIG. 1 but showing a fourth preferredform of integrated circuit having a pair of Hall-effect elementsaccording to the invention.

FIG. 11 is a fragmentary plan view similar to FIG. 1 but showing a fifthpreferred form of integrated circuit according to the invention.

BEST MODE FOR CARRYING OUT THE INVENTION First Mode

The first mode for carrying out the invention will now be described withreference to FIGS. 1 through 6. As is apparent from FIG. 1, theintegrated circuit 1 illustrated therein as an example of semiconductordevice according to the invention comprises a first and a secondHall-effect elements (hereinafter referred to as the Hall elements) 2and 3, a semiconductor element 4, a conductor layer 5 providing apassageway for an electric current to be measured, a control currentsupply circuit 64 for supplying control currents to the first and secondHall elements 2 and 3, an output circuit 21 for processing outputs fromthe Hall elements 2 and 3, a control circuit 60 for the semiconductorelement 4, and a first, a second and a third terminal 61, 62 and 63. InFIG. 1 the constituent elements and blocks of the integrated circuit 1are shown as blocks, and their details are not shown. In thisspecification the primary parts of Hall effect elements, comprisingsemiconductor regions and electrodes formed thereon, will becollectively called Hall-effect elements or Hall elements.

FIG. 2 is an illustration of the details of the electric circuitry ofthe FIG. 1 integrated circuit 1 as well as a d.c.-to-d.c. converterusing the same. A semiconductor element 4, a circuit element of theintegrated circuit 1, takes the form of a transistor acting as aswitching element of the d.c.-to-d c. converter. One terminal(collector) of this semiconductor element 4 is connected to one terminalof a d.c. power supply 66 via a primary winding 65 of a transformer 64.The other terminal (emitter) of the semiconductor element 4 is connectedto the other terminal of the d.c. power supply 6 by way of a conductorconstituted of the conductive layer 5 providing the passageway for thecurrent under measurement. The semiconductor element 4 has a controlterminal (base) connected to the control circuit 60. The control circuit60 produces a control circuit for on-off control of the semiconductorelement 4. A smoothing capacitor 69 is connected to the secondarywinding 67 of a transformer 64 via a rectifying diode 68. A pair ofoutput terminals 70 and 71, connected across the smoothing capacitor 69,are for connection of a load, not shown, therebetween. The d.c. outputvoltage between the pair of output terminals 70 and 71 is also appliedto the control circuit 60 thereby to be used for holding the d.c. outputvoltage constant.

The first and second Hall elements 2 and 3 are both disposed along thecurrent passageway conductor layer 5 for detection of the current Isflowing through the semiconductor element 4. For supplying the knowncontrol currents to the first and second Hall elements 2 and 3, theknown control current supply circuit 64 is connected to the first pairof electrodes 16 a and 17 a of the first Hall element 2 and to the firstpair of electrodes 16 b and 17 b of the second Hall element 3. Designedto provide a voltage corresponding to the current Is under measurementby combining the output voltages of the two Hall elements 2 and 3, theoutput circuit 21 comprises a first, a second, and a third differentialamplifier 29, 30 and 31. The first differential amplifier has a positiveinput connected to one second electrode 18 a of the first Hall element2, and a negative input connected to another second terminal 19 a of thefirst Hall element 2. The second differential amplifier 30 has apositive input connected to one second electrode 18 b of the second Hallelement 3, and a negative input connected to another second terminal 19b of the second Hall element 3. Consequently, the first Hall voltage Vh₁obtained from the first differential amplifier 29 is opposite inpolarity to the second Hall voltage−Vh₂ obtained from the seconddifferential amplifier 30. The third differential amplifier 31 has apositive input connected to the first differential amplifier 29, and anegative input connected to the second differential amplifier 30. Thusthe third differential amplifier 31 provides the output,Vh₁−(−Vh₂)=Vh₁+Vh₂. In other words, the third differential amplifier 31,an arithmetic means, provides the sum of the absolute value of theoutput Vh₁ from the first differential amplifier 29 and the absolutevalue of the output −Vh₂ from the second differential amplifier 30.

Incidentally, an output representative of (Vh₁+Vh₂) could be obtained byproviding an inverter circuit on the output stage of the seconddifferential amplifier 30, and an adder in place of the thirddifferential amplifier 31.

The semiconductor substrate 6 with the first and second Hall elements 2and 3, semiconductor 4, etc., thereon is formed from a semiconductorwafer having a p-type (first conductivity type) semiconductor substratein the form of, for example, monocrystaline sheet silicon with n-type(second conductivity type) silicon grown epitaxially thereon. In FIGS. 4and 5 the lower p-type semiconductor region 7 of the semiconductorsubstrate 6 is a substrate region, and the upper n-type mainsemiconductor regions 8 a, 8 b and 8 c and the P-type isolation regions9 therebetween are epitaxially grown regions. The p-type isolationregions 9 are formed by p-type impurity diffusion in type epitaxiallygrown regions. The first and second n-type main semiconductor regions 8a and 8 b for providing the first and second Hall elements 2 and 3 arejuxtaposed via the isolation region 9. The regions 7, 8 a, 8 b and 9could all be the other way around in conductivity type.

The first and second n-type semiconductor regions (hereinafter referredto as the “Hall semiconductor regions”) 8 a and 8 b, for giving the Halleffect to the first and second Hall elements 2 and 3, are islandssurrounded by the p-type semiconductor region 7 and p-type isolationregion 9, cruciate in shape as seen n a plan view as in FIG. 6. In thefirst Hall semiconductor region 8 a there are formed a pair of n-typesemiconductor regions 10 a and 11 a for supplying control current, apair of n-type semiconductor regions 12 a and 13 a for Hall voltagedetection, and a pair of p-type semiconductor regions 14 a and 15 a. Inthe second Hall semiconductor region 8 b, as in the first Hallsemiconductor region 8 a, there are provided a pair of n-typesemiconductor regions 10 b and 11 b for supplying control current, apair of n-type semiconductor regions 12 b and 13 b for Hall voltagedetection, and a pair of p-type semiconductor regions 14 b and 15 b. Thefirst and second Hall elements 2 and 3 are essentially alike inconstruction, so that like parts are identified by like referencenumerals, only with a suffixed to the reference numerals of one Hallelement, and b suffixed to the reference numerals of the other Hallelement, by way of distinction therebetween. Only one Hall element 2will be explained in detail, and the other Hall element 3 not.

In the first Hall element 2, the pair of control current supplysemiconductor regions 10 a and 11 a are formed by n-tpe impuritydiffusion adjacent the both ends of the Hall semiconductor region 8 a,which constitutes the primary part of this Hall element 2, in itslongitudinal direction or in the direction of the y-axis in FIG. 6. Thepair of control current supply semiconductor regions 10 a and 11 a arehigher in impurity concentration than the Hall semiconductor region 8 aThe first pair of electrodes 16 a and 17 b are in ohmic contact with thepair of semiconductor regions 10 a and 11 a. Centrally of the Hallsemiconductor region 8 a in the direction of the taxis in FIG. 6, andadjacent opposite ends thereof, the pair of p-type semiconductor regions14 a and 15 a are formed by p-type impurity diffusion. These p-typesemiconductor regions 14 a and 15 a are for limiting the areas ofcontact of the pair of Hall-voltage-detecting n-type semiconductorregions 12 a and 13 a with the Hall semiconductor region 8 a Formed byn-type impurity diffusion, the pair of Hall-voltage-detectingsemiconductor regions 12 a and 13 a are disposed adjacent the Hallsemiconductor region 8 a via the p-type semiconductor regions 14 a and15 a These Hall-voltage-detecting n-type semiconductor regions 12 a and13 a are higher in impurity concentration than the Hall semiconductorregion 8 a The second pair of electrodes 18 a and 19 a are in ohmiccontact with the n-type semiconductor regions 12 a and 13 a. That partof the Hall semiconductor region 8 a which lies between the pair ofHall-voltage-detecting semiconductor regions 12 a and 13 a are at rightangles with that part of the Hall semiconductor region 8 a which liesbetween the pair of control-current-supplying semiconductor regions 10 aand 11 a

As illustrated in both FIGS. 4 and 5, an insulating film 20 is providedon one main surface of the semiconductor substrate 6. Through aperturesformed in this insulating film 20, the first pair of electrodes 16 a and17 a make ohmic contact with the pair of n-typecontrol-current-supplying semiconductor regions 10 a and 11 a, and thesecond pair of electrodes 18 a and 19 a make ohmic contact with the pairof n-type Hall-voltage-detecting semiconductor regions 12 a and 13 a Thefirst pairs of electrodes 16 a sand 17 a, and 16 b and 17 b, of the fistand second Hall elements 2 and 3 are connected to the control currentsupply circuit 64 shown in FIG. 2. Also, the second pairs of electrodes18 a and 19 a, and 18 b and 19 b, of the first and second Hall elements2 and 3 are connected to the Hall-voltage-detecting output circuit 21,as illustrated in FIG. 2.

In order to provide a current detector constituted of the first andsecond Hall elements 2 and 3, the conductor layer 5 for the passage of acurrent under measurement is provided on the insulating film 20. As seenin a direction normal to one main surface of the semiconductor substrate6 shown in FIG. 3, or as seen in a plan view, the conductor layer 5 isso formed as to nearly surround the first and second Hall semiconductorregions 8 a and 8 b of the first and second Hall elements 2 and 3 and toextend between the first and second Hall semiconductor regions 8 a and 8b. More specifically, the conductor layer 5 comprises a first portion 5a in the shape of a U surrounding the fist Hall semiconductor region 8a, a second portion 5 b also in the shape of a U surrounding the secondHall semiconductor region 8 b a third portion 5 c bridging the first andsecond portions 5 a and 5 b, and a fourth and a fifth portion 5 d and 5e extending from the first and the second portion 5 a and 5 b The first,second and third portions 5 a, 5 b and 5 c as a whole is in the shape ofan S. As illustrated in FIG. 1, the conductor layer 5 is connected tothe semiconductor element 4, so that the current Is flows through thesemiconductor element 4 and the conductor layer 5.

As schematically illustrated in FIGS. 3, 5 and 6, the semiconductorelement 4 is formed on the same semiconductor substrate 6 as the firstand the second Hall element 2 and 3. That is, in FIGS. 3, 5 and 6, thereis shown as the semiconductor element 4 a transistor of knownconfiguration comprising an n-type emitter region 22, a p-type baseregion 23, an n-type collector region 24, an n⁺-type collector region25, an emitter electrode 26, a base electrode 27, and a collectorelectrode 28. The known control current supply circuit 64, outputcircuit 21, and control circuit 60, all shown in FIGS. 1 and 2, are alsoconventionally formed on the semiconductor substrate 6. The conductorlayer 5 disposed along the fist and second Hall elements 2 and 3 is ametallic layer formed concurrently with other conductor layers, notshown, formed on the insulating film 20 for wiring purposes.

The current Is of the semiconductor element 4 flows through theconductor layer 5 as indicated by the arrow in FIG. 3 by way of example,that is, from the fourth portion 5 d to the fifth portion 5 e of theconductor layer 5. The result, according to Ampere's right-handed screwrule, is the creation of the magnetic lines of force H, or magneticflux, oriented in the arrow-marked direction in FIG. 4.

As is apparent from the direction of the magnetic lines of force H inFIG. 2, the magnetic lines of force H acting on the Hall semiconductorregion 8 a of the first Hall element 2 is opposite in direction to themagnetic lines of force H acting on the Hall semiconductor region 8 b ofthe second Hall element 3. During current measurement, as is well known,a control current Ic is made to flow between the first pairs ofelectrodes 16 a and 17 a, and 16 b and 17 b, of the first and secondHall elements 2 and 3. Since the direction of the magnetic lines offorce H is at right angles with the direction of the control current IC,the first and second Hall voltages Vh₁ and −Vh₂ are generatedrespectively between the second pairs of electrodes 18 a and 19 a, and18 b and 19 b, of the first and second Hall elements 2 and 3. Theabsolute values of the first and second Hall voltages Vh₁ and −Vh₂ areproportional to the magnitude of the current flowing through theconductor layer 5. As the first and second differential amplifiers 29and 30 provide the first and second Hall voltages Vh₁ and −Vh₂ ofopposite polarities, the third differential amplifier 31 provides theoutput Vh₁+Vh₂, that is, the sum of the absolute values of the outputvoltages of the first and second Hall elements 2 and 3. The first andsecond Hall elements 2 and 3 are the same in pattern, so that the firstand second Hall voltages Vh₁ and Vh₂ are substantially equal to eachother. Consequently, the output from the third differential amplifier 31is 2Vh₁, twice the output from each Hall element.

The above described mode of carrying out the invention possesses thefollowing advantages:

(1) The conductor layer 5 for the passage of an electric current to bemeasured is formed on the insulating film 20 on the surface of thesemiconductor substrate 6 having the first and second Hall elements 2and 3, the conductor layer being disposed adjacent the Hall elements 2and 3, so that the passageway for the current under measurement isdisposed close to the Hall elements 2 and 3, resulting in theenhancement of sensitivity for detecting the current Is.

(2) The conductor layer 5 as the passageway for the current undermeasurement is so arranged as to surround approximately 90 percent ofthe peripheries of the Hall elements 2 and 3. Consequently, the magneticfields or magnetic lines of force H can be made to act on the first andsecond Hall semiconductor regions 8 a and 8 b from the directions of allthe four sides of the first and second Hall semiconductor regions 8 aand 8 b which are approximately rectangular in shape as seen in a planview. As large amounts of magnetic flux thus act effectively on thefirst and second Hall semiconductor regions 8 a and 8 b, the current Iscan be detected more accurately than heretofore.

(3) Current detection sensitivity is enhanced as there is obtained thesum of the absolute values of the outputs from the first and second Hallelements 2 and 3.

(4) The space requirement of the integrated circuit 1 is reduced as thefirst and second Hall elements 2 and 3 share the third portion 5 c ofthe conductor region 5.

(5) The first and second Hall elements are juxtaposed to provide acombined output, and the conductor layer 5 surround the first and secondHall elements 2 and 3 in opposite directions, so that current detectionis possible with little or no influence of external magnetic fields assuch fields counteract each other when applied to the fist and secondHall elements 2 and 3. Let V_(o) be the Hall voltage due to anextraneous magnetic field. Then the output from the first differentialamplifier 29 will be Vh₁+V_(o), the output from the second differentialamplifier 30 −Vh₂+V_(o), and the output from the third differentialamplifier 31 Vh₁+V_(o)−(−Vh₂+V_(o))=Vh₁+Vh₂. The output will be littleaffected by the extraneous magnetic fields, resulting in the enhancementof accuracy with which the current Is is detected.

(6) The conductor layer 5 can be fabricated concurrently with thefabrication of another necessary conductor layer of the integratedcircuit 1, without adding much to its manufacturing cost. It istherefore less expensive than prior art integrated circuits or the likeutilizing gigantic magnetoresistive effect elements.

Second Mode

The second preferred form of integrated circuit la including Hallelements according to the invention will now be described with referenceto FIGS. 7 and 8. Those parts of this integrated circuit 1 a which havelike parts in the FIGS. 1 through 6 embodiment will be identified bylike reference characters, and their description will be omitted.

The integrated circuit 1 a of FIGS. 7 and 8 newly comprises aninsulating layer 40 and a magnetic collector plate 41 fabricated from amaterial of high magnetic permeability such as Fe, Ni, or Fe-Ni alloy,the other details of construction being akin to those of the FIGS. 1through 6 integrated circuit 1. As is apparent from a consideration ofFIG. 8, the insulating layer 40 is so formed as to cover the electrodes16 a, 16 b, 17 a, 17 b, 18 a, 18 b, 19 a and 19 b, insulating film 20,and conductor layer 5.

The magnetic collector plate 41 overlies the insulating layer 40. Beinghigher than air in magnetic permeability, the magnetic collector plate41 contributes to the improvement of the sensitivity of the Hallelements 2 and 3 by favorably directing to the Hall semiconductorregions 8 a and 8 b the magnetic flux that has been created by thecurrent flowing in the conductor layer 5. The collector plate 41 shouldbe so arranged as to completely cover the first and second Hall elements2 and 3 and conductor layer 5 for collecting all of the magnetic fluxgenerating from the current-carrying conductor layer 5.

Third Mode

FIG. 9 is a plan view similar to FIG. 1 but showing a third preferredform of integrated circuit 1 b according to the invention. Theintegrated circuit 1 b of FIG. 9 is similar to the FIG. 1 integratedcircuit 1 except for the absence of the semiconductor element 4 andcontrol circuit 60. Therefore, in FIG. 9, parts having correspondingparts in FIGS. 1 through 9 will be identified by like referencecharacters, and their description omitted.

The integrated circuit 1 b of FIG. 9 is an integration of the first andsecond Hall elements 2 and 3, the conductor layer 5 providing the pathfor the current to be measured, the control current supply circuit 64,and the output circuit 21, on the common semiconductor substrate 6 a Therelationship between the first and second Hall elements 2 and 3 and theconductor layer 5 in FIG. 9 is the same as that of FIG. 1, so that theFIG. 9 integrated circuit 1 b gains the same advantages as does the FIG.1 integrated circuit 1.

Fourth Mode

FIG. 10 shows a fourth preferred form of integrated circuit 1 caccording to the invention, having the first and second Hall elements 2and 3. The integrated circuit 1 c is formed by omitting the controlcurrent supply circuit 64 and control circuit 21 from the FIG. 6integrated circuit 1 b and is similar in the other details ofconstruction to that of FIG. 9. Therefore, the parts havingcorresponding parts in FIG. 9 will be identified by like referencecharacters in FIG. 10, and their description will be omitted. In FIG. 10the electrodes 16 a, 16 b, 17 a, 17 b, 18 a, 18 b, 19 a and 19 b areindicated by broken lines.

The FIG. 10 integrated circuit 1 c posses the first and second Hallelements 2 and 3 and the conductor layer 5 like those of FIGS. 1 and 9,so that they offer the same advantages as do the FIGS. 1 and 9integrated circuits 1 and 1 b.

Also, in the FIG. 10 integrated circuit 1 c, the second electrode 19 aof the first Hall element 2 and the second electrode 19 b of the secondHall element 3 can be electrically interconnected, and a Hall voltagedetection signal can be obtained from between the second electrode 18 aof the first Hall element 2 and the second electrode 18 b of the secondHall element 3. In this case there can be obtained from between theelectrodes 18 a and 18 b the addition, Vh₁+Vh₂, of the first and secondHall voltages Vh₁ and Vh₂ of the first and second Hall elements 2 and 3.

Also, in the FIG. 10 integrated circuit 1 c, the second electrode 18 aof the first Hall element 2 and the second electrode 18 b of the secondHall element 3 can be electrically interconnected, and the addition,Vh₁+Vh₂, of the first and second Hall voltages Vh₁ and Vh₂ of the firstand second Hall elements 2 and 3 can be obtained from between the secondelectrode 19 a of the first Hall element 2 and the second electrode 19 bof the second Hall element 3.

Fifth Mode

FIG. 11 shows a fifth preferred form of integrated circuit 1 d accordingto the invention, which is similar to the FIGS. 7 and 9 integratedcircuit 1 a except for the patterns of the first and second Hallsemiconductor regions 8 a and 8 b and the current path conductor layer5. Therefore, those parts of this integrated circuit 1 d which havetheir counterparts in FIGS. 7 and 8 will be identified by like referencecharacters, and their description will be omitted.

FIG. 11 does not show the details of the first and second Hall elements2 and 3 but does show the patterns of the fall semiconductor regions 8 aand 8 b which have been herein modified into hexagonal shape.

The current path conductor layer 5 of FIG. 11 is formed to include anarrow portion 50 and a pair of wide portions 51 and 52. The narrowportion 50 is disposed between the pair of Hall elements 2 and 3, andthe wide portions 51 and 52 are disposed away from the Hall elements.The collector plate 41 is disposed as in FIG. 7 over the two Hallelements 2 and 3 and the conductor layer 5.

The FIG. 11 integrated circuit 1 d posses the following advantages inaddition to those gained in the first and the second mode:

1. As the current density is made higher in the narrow portion 50, themagnetic flux generated due to the current flowing in the narrow portion50 of the current path conductor layer 5 can be made to act effectivelyon the Hall elements 2 and 3, resulting in further improvement of thecurrent-detecting sensitivity.

2. The conductor layer 5 a with its wide portions 51 and 52 favorablyradiates heat, making it possible to detect currents of greatermagnitude.

3. The space requirement of the integrated circuit 1 d is reduced as thecurrent path conductor layer 5 is disposed between, and shared by, thetwo Hall elements 2 and 3.

The present invention is not to be limited by the details of the abovedescribed modes of carrying out the invention but admits ofmodifications such as the following:

1. The embodiments of FIGS. 1 through 11 could dispense with either ofthe two Hall elements 2 and 3 and detect a current with the remainingone only. If the first Hall element 2 is to be left in the integratedcircuits 1, 1 a, 1 b and 1 c of FIGS. 1 through 10, the current shouldpreferably be made to flow through the first and third portions 5 a and5 c of the conductor layer 5. Alternatively, three or more Hall elementscould be provided to obtain the combined output therefrom.

2. In FIGS. 1 through 10 the conductor layer 5 could be constituted ofonly the third portion 5 c between the Hall elements 2 and 3. Thisarrangement also can curtail the effects of external magnetic fields(noise). The conductor layer 5 should preferably surround one half ormore of the periphery of each of the Hall elements 2 and 3.

3. The magnetic collector 41 could be provided only in limited regionsabove the Hall semiconductor regions 8 a and 8 b.

4. The magnetic collector 41 could be replaced by that in the form of aferrite-containing resin layer provided on the Hall elements 2 and 3.

5. The conductor layer could be formed in the form of coils by the knownlamination technology, and the Hall elements 2 and 3 surrounded by thesecoils.

Industrial Applicability

as is apparent from the foregoing, the semiconductor devices having ahall element or elements find use for current measurement of electriccircuits such as switching regulators.

What is claimed is:
 1. A semiconductor device for measurement of anelectric current in an electric circuit, characterized by comprising: asemiconductor substrate having a Hall-effect element; an insulating filmdisposed on a surface of said semiconductor substrate; a conductor layerdisposed on said insulating film so as to extend along said Hall-effectelement as seen in a plan view and so formed as to permit the flowtherethrough of an electric current of said electric circuit; aninsulation layer disposed on said conductor layer; and a magneticcollector plate disposed on said insulation layer so as to direct tosaid Hall-effect element a magnetic flux that has been generated by thecurrent carried by said conductor layer.
 2. A semiconductor device asclaimed in claim 1, characterized in that said conductor layer surroundsnot less than one half of the periphery of said Hall-effect element. 3.A semiconductor device as claimed in claim 1 or 2, characterized in thatsaid semiconductor substrate has another circuit element, and that saidconductor layer is connected to said other circuit element so that acurrent flows through said other circuit element and said conductorlayer.
 4. A semiconductor device for measurement of an electric currentin an electric circuit, characterized by comprising: a semiconductorsubstrate having a first and a second Hall-effect element; an insulatingfilm disposed on a surface of said semiconductor substrate; a conductorlayer disposed on said insulating film so as to apply to said firstHall-effect element a magnetic field oriented in a first direction andto said second Hall-effect element a magnetic field oriented in a seconddirection opposite to said first direction, said conductor layer beingso formed as to permit the flow therethrough of an electric current ofsaid electric circuit; an insulation layer disposed on said conductorlayer; and a magnetic collector plate disposed on said insulation layerso as to direct said Hall-effect element a magnetic flux that has beengenerated by the current carried by said conductor layer.
 5. Asemiconductor device as claimed in claim 4, characterized in that saidconductor layer is formed to comprise: a U-shaped first portionsurrounding said first Hall-effect element; a U-shaped second portionsurrounding said second Hall-effect element; and a third portiondisposed between said first and second Hall-effect elements andinterconnecting said first and second portions.
 6. A semiconductordevice as claimed in claim 4 or 5, characterized in that said outputmeans comprises: a first amplifier connected to said first Hall-effectelement; a second amplifier connected to said second Hall-effectelement; and arithmetic means connected to said first and secondamplifiers for providing the sum of the absolute values of outputs fromsaid first and second amplifiers.
 7. A semiconductor device as claimedin claim 4 or 5, wherein said semiconductor substrate has anothercircuit element, characterized in that said conductor layer is connectedto said other circuit element so that the current that has flowedthrough said other circuit element may flow through said conductorlayer.